Scale Drawings
Aligned to 7.G.A.1 — Common Core State Standards for Mathematics.
What this lesson teaches
A scale drawing uses a scale factor to relate drawing lengths to actual lengths. Multiply a drawing length by the scale to get the real length. Areas scale by the square of the scale factor.
Worked example
A map uses 1 cm = 20 km. A road measures 3.5 cm on the map. Actual length = 3.5 × 20 = 70 km.
Practice questions
- A model car uses a scale of 1:24. If the model is 8 cm long, how long is the real car in cm?
- A blueprint scale is 1 in = 4 ft. A wall is 6.5 in on paper. Find its real length.
- A drawing is enlarged by a scale factor of 3. How many times larger is its area?
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Dibujos a Escala
Un dibujo a escala usa un factor de escala para relacionar las longitudes del dibujo con las reales. Multiplica una longitud del dibujo por la escala para obtener la longitud real. Las áreas se escalan por el cuadrado del factor de escala.
Ejemplo: Un mapa usa 1 cm = 20 km. Un camino mide 3.5 cm en el mapa. Longitud real = 3.5 × 20 = 70 km.
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